Psoriasis: Diagnosis
Psoriasis is a chronic skin disease that causes red, scaly plaques anywhere on the body. It can decrease the quality of life, but there are effective treatments to control it.
How is psoriasis diagnosed?
Psoriasis is a disease that usually is diagnosed by examining the affected skin. The difficulty in psoriasis is to distinguish it from other skin diseases. Usually the physician will be able to recognize psoriasis by examining your skin closely, but sometimes a small piece of skin (biopsy) may be needed in order to examine it in greater detail under a microscope. Unfortunately, not all general practitioners are familiar with the various forms of psoriasis, and oftentimes a dermatologist is needed to confirm the diagnosis.
To support the diagnosis of psoriasis, the doctor will ask you questions about your family history, that is, if other people in your family have psoriasis.
It is also very important for you to tell the doctor in case that you suffer back pain or pain in other joints and stiffness.
How is evaluated the psoriasis’ severity?
The doctor will examine the skin throughout the entire body for two purposes. First, to make sure that the spots are in fact psoriasis and second, to determine their intensity (grade of redness, flaking, etc.) and extension (the percentage of affected skin). Intensity and extension are two of the factor that the doctor uses to determine the severity of psoriasis. These are usually combined in indexes and scales. Some of the indexes most used by dermatologists are PASI (psoriasis area and severity index) and BSA (body surface area).
Equally important is to find out the psychological toll that psoriasis takes on your quality of life; and how it impacts your physical and psychological well-being and your social relationships. As this is something only the patient knows, the doctor will conduct a series of questions and ask you to fill in a quality of life questionnaire.
Based on these factors, Psoriasis can be classified from mild, moderate to severe. Your doctor needs to ascertain the type and grade of your psoriasis to determine what the best medical treatment for your condition is, and to evaluate how psoriasis responds to such treatment over time.
References
- European Academy of Dermatology and Venereology (EADV). Psoriasis, a closer look [Internet]. 2019. Available at: https://eadv.org/cms-admin/showfile/9635-EADV%20PSORIASIS-1-A%20closer%20look.pdf
- National Institute for Health and Care Excellence (NICE). Psoriasis: assessment and management. Clinical guideline [CG153] [Internet]. 2012 [Updated 2017]. Available at: https://www.nice.org.uk/guidance/cg153/resources/psoriasis-assessment-and-management-pdf-35109629621701